It takes a different mentality than your typical relationship. First of all, you cannot be at all jealous, if you have any amount of jealousy in you, you cannot date a porn star. Just remember that at the end of the day, she or he is coming back to you. That makes you pretty damn special.
There must be trust and a lot of trust. You must trust her to know what is best for her body. You must trust her to know what is best for your relationship. You must trust her to know what is best for her.
There can be no insecurity. She chooses to be with you. Feel good about that. She's going to meet other men its part of her job. She's going to meet a better lover that’s also part of her job. Do not become insecure. See this and accept this as part of the relationship.
You must be highly empathic. You become empathic by listening to her. And I don't mean you just sit there while she talks to you. You listen to her words and you become part of her world. Then anticipate her needs and meet them. This is true for any relationship.
Know it is a job
You must realize that porn is a job. Not many people like to bring their work home with them. While you might reap the benefits of her skills, you're also probably not going to get into random three-ways with her set partners, or orgies, or gang-bangs. In fact you may just end up having less sex than other people, because she regularly comes home from the set having had sex for six to eight hours, and now she just wants to cuddle in front of the TV and watch some mindless entertainment to forget about all the fantastic sex she just had.